U.S. Pat. Nos. 4,122,274 and 4,209,620 describe 3-(1H-tetrazol-5-yl)-4H-pyrido[1,2-a-]pyrimidin-4-ones and the antiallergy activity exhibited by such compounds. U.S. Pat. No. 4,223,031 describes 3-(1H-tetrazol-5-yl)-4H-pyrimido[2,1-b]benzothiazol-4-ones and 6-(1H-tetrazol-5-yl)thiazolo[3,2-a]pyrimidin-5-ones and the antiallergy activity exhibited by such compounds. Sam and Plampin, J. Pharm. Sci., 53, 538 (1964) describes substituted 2-aminobenzoxazoles and substituted benzoxazolinones which are skeletal muscle relaxants.